xref: /freebsd/crypto/openssh/openbsd-compat/bsd-openpty.c (revision 74bf4e164ba5851606a27d4feff27717452583e5)
1 /*
2  * Please note: this implementation of openpty() is far from complete.
3  * it is just enough for portable OpenSSH's needs.
4  */
5 
6 /*
7  * Copyright (c) 2004 Damien Miller <djm@mindrot.org>
8  *
9  * Permission to use, copy, modify, and distribute this software for any
10  * purpose with or without fee is hereby granted, provided that the above
11  * copyright notice and this permission notice appear in all copies.
12  *
13  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
14  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
15  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
16  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
17  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
18  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
19  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
20  */
21 
22 /*
23  * Author: Tatu Ylonen <ylo@cs.hut.fi>
24  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
25  *                    All rights reserved
26  * Allocating a pseudo-terminal, and making it the controlling tty.
27  *
28  * As far as I am concerned, the code I have written for this software
29  * can be used freely for any purpose.  Any derived versions of this
30  * software must be clearly marked as such, and if the derived work is
31  * incompatible with the protocol description in the RFC file, it must be
32  * called by a name other than "ssh" or "Secure Shell".
33  */
34 
35 #include "includes.h"
36 #if !defined(HAVE_OPENPTY)
37 
38 #ifdef HAVE_UTIL_H
39 # include <util.h>
40 #endif /* HAVE_UTIL_H */
41 
42 #ifdef HAVE_PTY_H
43 # include <pty.h>
44 #endif
45 #if defined(HAVE_DEV_PTMX) && defined(HAVE_SYS_STROPTS_H)
46 # include <sys/stropts.h>
47 #endif
48 
49 #ifndef O_NOCTTY
50 #define O_NOCTTY 0
51 #endif
52 
53 int
54 openpty(int *amaster, int *aslave, char *name, struct termios *termp,
55    struct winsize *winp)
56 {
57 #if defined(HAVE__GETPTY)
58 	/*
59 	 * _getpty(3) exists in SGI Irix 4.x, 5.x & 6.x -- it generates more
60 	 * pty's automagically when needed
61 	 */
62 	char *slave;
63 
64 	if ((slave = _getpty(amaster, O_RDWR, 0622, 0)) == NULL)
65 		return (-1);
66 
67 	/* Open the slave side. */
68 	if ((*aslave = open(slave, O_RDWR | O_NOCTTY)) == -1) {
69 		close(*amaster);
70 		return (-1);
71 	}
72 	return (0);
73 
74 #elif defined(HAVE_DEV_PTMX)
75 	/*
76 	 * This code is used e.g. on Solaris 2.x.  (Note that Solaris 2.3
77 	 * also has bsd-style ptys, but they simply do not work.)
78 	 */
79 	int ptm;
80 	char *pts;
81 	mysig_t old_signal;
82 
83 	if ((ptm = open("/dev/ptmx", O_RDWR | O_NOCTTY)) == -1)
84 		return (-1);
85 
86 	/* XXX: need to close ptm on error? */
87 	old_signal = signal(SIGCHLD, SIG_DFL);
88 	if (grantpt(ptm) < 0)
89 		return (-1);
90 	signal(SIGCHLD, old_signal);
91 
92 	if (unlockpt(ptm) < 0)
93 		return (-1);
94 
95 	if ((pts = ptsname(ptm)) == NULL)
96 		return (-1);
97 	*amaster = ptm;
98 
99 	/* Open the slave side. */
100 	if ((*aslave = open(pts, O_RDWR | O_NOCTTY)) == -1) {
101 		close(*amaster);
102 		return (-1);
103 	}
104 
105 #ifndef HAVE_CYGWIN
106 	/*
107 	 * Try to push the appropriate streams modules, as described
108 	 * in Solaris pts(7).
109 	 */
110 	ioctl(*aslave, I_PUSH, "ptem");
111 	ioctl(*aslave, I_PUSH, "ldterm");
112 # ifndef __hpux
113 	ioctl(*aslave, I_PUSH, "ttcompat");
114 # endif /* __hpux */
115 #endif /* HAVE_CYGWIN */
116 
117 	return (0);
118 
119 #elif defined(HAVE_DEV_PTS_AND_PTC)
120 	/* AIX-style pty code. */
121 	const char *ttname;
122 
123 	if ((*amaster = open("/dev/ptc", O_RDWR | O_NOCTTY)) == -1)
124 		return (-1);
125 	if ((ttname = ttyname(*amaster)) == NULL)
126 		return (-1);
127 	if ((*aslave = open(ttname, O_RDWR | O_NOCTTY)) == -1) {
128 		close(*amaster);
129 		return (-1);
130 	}
131 	return (0);
132 
133 #elif defined(_UNICOS)
134 	char ptbuf[64], ttbuf[64];
135 	int i;
136 	int highpty;
137 
138 	highpty = 128;
139 #ifdef _SC_CRAY_NPTY
140 	if ((highpty = sysconf(_SC_CRAY_NPTY)) == -1)
141 		highpty = 128;
142 #endif /* _SC_CRAY_NPTY */
143 
144 	for (i = 0; i < highpty; i++) {
145 		snprintf(ptbuf, sizeof(ptbuf), "/dev/pty/%03d", i);
146 		snprintf(ttbuf, sizeof(ttbuf), "/dev/ttyp%03d", i);
147 		if ((*amaster = open(ptbuf, O_RDWR|O_NOCTTY)) == -1)
148 			continue;
149 		/* Open the slave side. */
150 		if ((*aslave = open(ttbuf, O_RDWR|O_NOCTTY)) == -1) {
151 			close(*amaster);
152 			return (-1);
153 		}
154 		return (0);
155 	}
156 	return (-1);
157 
158 #else
159 	/* BSD-style pty code. */
160 	char ptbuf[64], ttbuf[64];
161 	int i;
162 	const char *ptymajors = "pqrstuvwxyzabcdefghijklmno"
163 	    "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
164 	const char *ptyminors = "0123456789abcdef";
165 	int num_minors = strlen(ptyminors);
166 	int num_ptys = strlen(ptymajors) * num_minors;
167 	struct termios tio;
168 
169 	for (i = 0; i < num_ptys; i++) {
170 		snprintf(ptbuf, sizeof(ptbuf), "/dev/pty%c%c",
171 		    ptymajors[i / num_minors], ptyminors[i % num_minors]);
172 		snprintf(ttbuf, sizeof(ttbuf), "/dev/tty%c%c",
173 		    ptymajors[i / num_minors], ptyminors[i % num_minors]);
174 
175 		if ((*amaster = open(ptbuf, O_RDWR | O_NOCTTY)) == -1) {
176 			/* Try SCO style naming */
177 			snprintf(ptbuf, sizeof(ptbuf), "/dev/ptyp%d", i);
178 			snprintf(ttbuf, sizeof(ttbuf), "/dev/ttyp%d", i);
179 			if ((*amaster = open(ptbuf, O_RDWR | O_NOCTTY)) == -1)
180 				continue;
181 		}
182 
183 		/* Open the slave side. */
184 		if ((*aslave = open(ttbuf, O_RDWR | O_NOCTTY)) == -1) {
185 			close(*amaster);
186 			return (-1);
187 		}
188 		/* set tty modes to a sane state for broken clients */
189 		if (tcgetattr(*amaster, &tio) != -1) {
190 			tio.c_lflag |= (ECHO | ISIG | ICANON);
191 			tio.c_oflag |= (OPOST | ONLCR);
192 			tio.c_iflag |= ICRNL;
193 			tcsetattr(*amaster, TCSANOW, &tio);
194 		}
195 
196 		return (0);
197 	}
198 	return (-1);
199 #endif
200 }
201 
202 #endif /* !defined(HAVE_OPENPTY) */
203 
204